In silver halide color photosensitive materials, there are used light-sensitive silver halide emulsions and so-called dye-forming couplers (abbreviated as "couplers" hereinafter) which form dyes by reacting with the oxidation product of an aromatic primary amine developing agent. In general, color images are formed by the subtractive color process using a combination of yellow, magenta and cyan couplers.
As for the magenta couplers, the 5-pyrazolone type magenta couplers which contain an acylamino group or an anilino group at the 3-position and a phenyl group at the 1-position are well known. On the other hand, pyrazoloazole type magenta couplers have achieved a rapid development in recent years, and the practical use thereof in photosensitive materials for picture-taking purposes and in those for viewing purposes, such as color prints, color slide and color display, is now well under way because unlike conventional 5-pyrazolone type magenta couplers they have some desirable characteristics, for instance, they can provide excellent color reproducibility since the dyes formed therefrom have an absorption characteristic such that there is no secondary absorption in the wavelength region shorter than the wavelengths of their main absorption (about 430 nm), and they can provide color images of high fastness.
As for the cyan couplers, phenol type couplers and naphthol type couplers are well known. In recent years, however, various new couplers have been proposed with a progress of researches on couplers which have more desirable color-forming characteristics and can provide color images of higher fastness and more excellent color reproducibility with the intention of introducing improvements in the color formation characteristics of phenol type and naphthol type couplers (including coupling activities of the couplers and molar absorption coefficients of the dyes obtained therefrom) and in the fastness and the absorption characteristics of the color images obtained from the couplers of said types. Examples of such cyan couplers include the 3-hydroxypyridine compounds disclosed in EP-A-0033105, the 3H-2-dicyanomethylidenethiazoles disclosed in EP-A-0362808, the 3-dicyanomethylidene-2,3-dihydrobenzothiophene-1,1-dioxides disclosed in JP-A-64-32260 (the term "JP-A" as used herein means an "unexamined published Japanese patent application"), the pyrazoloazoles disclosed in JP-A-63-264753 and U.S. Pat. No. 4,873,183, the imidazoles disclosed in U.S. Pat. Nos. 4,818,672 and 4,921,783, JP-A-03-48243 and so on, the pyrazolopyrimidones and the pyrazoloquinazolones disclosed in EP-A-0304001, EP-A-0329036, EP-A-0374781 and JP-A-02-85851, and the ring-condensed triazoles disclosed in EP-A-0342637.
However, not all the desirable characteristics described above, including excellent color forming characteristics, high fastness of color image and excellent color reproducibility, are inherent in such new cyan couplers. Therefore, it is the state of things that further improvements and researches on those cyan couplers are required for practical use.
On the other hand, the couplers containing 1H-pyrrolo[1,2-b][1,2,4]triazole as a mother nucleus are described in the notes of lectures at the annual convention of Japanese Photographic Society in the 60th year of Showa (held on May 23 and 24 in 1985, at Shigaku Kaikan), pages 108-110, and disclosed in JP-A-62-279340 and JP-A-62-278552. Such couplers produce magenta dyes. Since these magenta dyes show broader absorption spectra than those produced from the foregoing pyrazolotriazole type magenta couplers, it cannot be said that said couplers provide satisfactory hue.
Although it is a fact that silver halide photosensitive materials excellent in reproducibility of colors of red series have been obtainable since the practical use of the foregoing pyrazolotriazole type magenta couplers got under way, there have been a further desire for silver halide photosensitive materials which ensure excellent reproducibility of colors of green series and blue series as well as red series and the prevention of stain after photographic processing to provide photographs retaining their beauty permanently.
As described above, even when cyan and magenta couplers which have undergone improvements in characteristics including color forming characteristics, fastness of color image produced therefrom, color reproducibility and so on are incorporated in photosensitive materials, it is a general tendency that not all the improved characteristics are used efficiently and, far from it, some of them occasionally bring about adverse results. For instance, even when the color reproducibility of a coupler is improved, the coupler cannot be practically used if it causes marked deterioration in the color reproducibility, e.g., by gradually staining the white area of the photosensitive material with the lapse of time after photographic processing, because it is inferior in image storage characteristics.